The Institute of Chemistry has developed a new strategy for structural color 3D printing

Three-dimensional photonic crystals have attracted attention due to their unique optical properties and have shown broad application prospects
in various fields.
3D printing technology provides the possibility
to construct complex three-dimensional photonic crystal structures.
However, the common inkjet printing, direct writing printing and fused deposition methods are limited by the degree of freedom to construct three-dimensional structures, the cumbersome and lengthy balanced coloring process, and the weak volumetric structural color properties, which hinder further applications
.
Although it has been reported that the rapid preparation of three-dimensional photonic crystals is achieved by using discontinuous 3D printing, the rough surface topography and low fidelity are difficult to meet the requirements of
optical devices.
Therefore, how to quickly prepare complex three-dimensional photonic crystal structures with smooth surfaces and bright volume structural colors through simple and easy methods is still a challenge
.

Recently, Song Yanlin, researcher of the Key Laboratory of Green Printing Institute, Institute of Chemistry, Chinese Academy of Sciences, and Wu Lei, associate researcher, etc.
, used hydrogen bond-assisted colloidal particle ink to realize the preparation
of three-dimensional photonic crystal structure with bright structural color based on continuous digital light processing (DLP) 3D printing technology.
The synergy of the uniform dispersion of colloidal particles induced by hydrogen bonding and the continuous curing method makes the colloidal particles confinement assembly in each cured layer during the continuous printing process, thereby giving the three-dimensional photonic crystal volume structure color characteristics
.
By controlling the particle size and printing speed of colloidal particles, the assembled structural color
can be finely tuned.
Based on this, complex three-dimensional structures with single or multiple structural colors can be quickly prepared, and optical transmission structures
with smooth inner and outer surfaces, low optical loss, pattern, and color control can be printed.
The three-dimensional photonic crystal structure printed by this method has angle-dependent characteristics, excellent shape fidelity, smooth surface morphology and high precision, which is of great significance for the preparation of
innovative structural colors and the application of extended 3D printing.

The research was published in Nature Communications
.
The research work is supported
by the Ministry of Science and Technology, the National Natural Science Foundation of China, the Chinese Academy of Sciences, and the Beijing National Research Center for Molecular Sciences.

3D structural color printers and various complex 3D photonic crystal structures and optical transmission structures